EFFECTS OF RAMIAL CHIPPED WOOD AMENDMENTS ON WEED CONTROL, SOIL PROPERTIES AND TOMATO CROP YIELD

There is growing interest in soil amendment with exogenous organic matter and especially with Ramial Chipped Wood (RCW). Environmentally friendly agricultural practices of this sort are well suited to tropical islands and are easily adopted given the ready availability of the necessary tree and woody-shrub resources. Field trials were conducted on a silty-clay soil and on a loamy-sand soil. In both cases, RCW applications (100 or 400 m³/ha) were incorporated into the soil and/or applied as a surface mulch. RCW applications significantly reduced weed development as a possible result of physical and/or allelopathic effects. To test the effects of RCW applications on crops, tomato seedlings were transplanted to a silty-clay soil four months after RCW application and grown on for a six-month period. The yield of marketable tomatoes was twice that of similar plants grown under control conditions. Impacts of RCW were also detected on the physico-chemical and biological properties of the soil, especially on microbial biomass and on mineralisation processes. The positive effects of RCW on tomato yield, weed control and soil properties suggest that RCW is a potentially good amendment for organic agriculture in tropical islands.